2008 Volvo C30 T5 acceleration and Idle

[mirroredeyes]

Just have a few questions... call me a hypochondriac person.... but

1) When slowing down to almost 0 km/h my engine rpm goes a little bit under the idle rpm and back up, i remember it usually going 1000-800 bobbing as it downshifts (automatic) but when i come to a halt it dips 650-800.. about 2 times. i just notice this when i put on my snow tires, i assume its the traction and resistance?

2) When in 3rd gear @ 60km/h accelerating to 100km/h around 3800rpm the rpm drops about 100 rpm and back up and it is audible. could this be due to all the electronics? air flow, MAF, ECU, Fuel mixture

3) when starting car and putting it into drive and drive for 5-10seconds i hear a flap under the car close or open.. does anyone hear that sound too

edit: It is about 20 Fahrenheit and windy like 40-50kmh winds
thanks

[MadeInJapan]

Sorry- I have a '07 S40 T5 and notice none of those things- or at least that I've noticed. Maybe others will chime in with different experiences.